Warm-ups and lead-ins. Are these the same thing or is there a difference between them? The term is often used interchangeably, but I would suggest that they each have different purposes, but that the same activity might be used in a lesson as both a warm-up and a lead-in.
Warm-ups are used at the beginning of a lesson. Their aim is the get the learners settled, "thinking in English" and fully "into" the lesson. They may have various aims - for example they might revise something that had been taught in a previous lesson, or focus on something that had been prepared for homework. For example, if the previous lesson had focused on making polite requests, the first section of the lesson might be spent getting the learners to repeat a roleplay that they had done then with a different partne (see Fahim et al, 2015, for reports on studies of the usefuless of task repetition), or performing a mingle activity based on various What would you say? situations which they had been given to prepare for homework. In the class, they would then each be given one of the situations and have to circulate amongst the other students, making their request and responding to the requests that were made to them.
If the activity is to act as a warm up, it's essential (except with very small classes of - eg of three or four learners) that it involves pairwork or group work, in order to ensure maximum learner involvement and participation. If the activity is done T/class with a larger group, then the only person liable to get "warm" will be the teacher. Individual learners simple won't be involved constantly enough for the activity to achieve the aims set above for warm-ups.
Here then, the Pw or mingle activity activity is acting as a warm up but not as a lead-in. On the contrary, its other purposes are to check learners' retention of and to consolidate work done previously. So what is a lead-in?
A lead-in aims to prepare learners for an activity that follows - often, but not necessarily, a skills activity. it may aim eg :
- to activate schemata on the topic of the activity
- to reactivate and/or feed in key language items which, if not understood or at the forefront of the learners' minds, could hinder their
Very often, this too can involve PW/GW. For example, a reading comprehension activity might be preceded by a PW/GW discussion asking the learners to talk about their own personal experience of the topic. This would allow both of the above aims to be achieved - with the teacher being able to identify any gaps in the learners' knowledge of the key items and feed them in either on-the-spot while monitoring, or in a follow up.
Clearly, if this were done at the beginning of the lesson, (instead of our consolidation activity) and with the reading comprehension as stage two, then this PW/GW discussion would serve the purposes of being both a warm-up and a lead-in at the same time.
Done later in the lesson, however, the teacher may feel s/he does not have time to set up, run and follow-up such an activity. Or she might suspect that no-one was likely to have had personal experience of the topic. The learners are already "warmed up" and into the lesson, and all s/he has to do now is scaffold the following activity. She might therefore opt for a much quicker lead-in at class level - eg ask the class Has anyone ever been hang-gliding? and if someone did say yes get them to talk about it briefly. If not (as is likely) ask a couple of questions which foreshadow the text (Would you like to? Why? Why not?) elicit a few answers and write them up. This would activate schemata, allow the teacher to focus on any key language items needed to understand the text, but take less time than a full discussion activity. Here the activity is acting as a lead-in, but not as a warm-up.
Fahim, M et al, 2015, The Effects of Task Repetition on Language Teaching and Learning: A Review, Humanising Language Teaching Magazine